Victims of the Alton Towers roller-coaster crash in which five people were seriously injured including two teenagers who lost legs were left waiting for 17 minutes before anyone called 999, a court has heard.

Stafford Crown Court was also told how staff responsible for operating the Smiler ride had not read the manual and that, although gale force winds were the ultimate cause of the crash, it was not fitted with a wind speed recorder.

A judge also heard how staff at the park also had a “distrust” of fault signals leading engineers to override a computer system which could have prevented the accident.

It also emerged that while the theme park’s operator, Merlin Attractions Operations, has accepted that “human errors” were responsible for the incident on June 2 last year, no one at the company has resigned as a result.

The court was shown CCTV footage of the moment of the crash in which altogether 16 people in total were injured.

The group has been told it is facing a fine potentially topping £10 million after admitting a health and safety breach leading to the accident.

Opening a two-day sentencing hearing, Bernard Thorogood, prosecuting, said the force of the collision between two carriages was equivalent to a 90mph car crash.

Vicky Balch, then 19, and Leah Washington, then 17, each lost a leg in the accident while several other people who were trapped for hours.

Mr Thorogood outlined how a test carriage had been sent around the rise but had come to rest in a valley of the track, unseen by staff.

Engineers then overrode a computer system, which they thought had stopped the ride in error, sending a full car along to the track and into the path of the empty carriage.

They speak of their disbelief and horror as they saw ahead up the track the train into which there were going to diveBernard Thorogood, for the HSE

“The subsequent collision was plain to see to some in the train,” he told the court, including the victims.

“I refer to those in the front row’s statements, where they speak of their disbelief and horror as they saw ahead up the track the train into which there were going to dive.”

The court heard that the collision between the two carriages happened at 1.51pm. But it was not until 2.08pm that emergency services were alerted with the first 999 call.

One of the features is not just the impact on those injured, but on those close to themJudge Michael Chambers QC

Judge Michael Chambers QC, the Recorder of Stafford, was also told that the Smiler was not fitted with anemometers record wind speeds, which 46mph on the day of the accident.

“The operational limit of the ride should be 34mph, that’s when it should stop.

“There's no other sensible explanation why the train stalled, it was wind speed that caused it.

“Another rollercoaster called Skyride had been closed at 12.15pm due to high gusting winds.”

A court hearing in April this year was told that Merlin had carried its own internal investigation following the incident, which established that a worker manually overrode the rollercoaster's governing computer system.

Alton Towers has instituted 30 changes following the crash to improve safety of the ride, the court heard.

Speaking about the potential fine to Merlin, Mr Thorogood said it could be between £3,000 and £10 million, but could be increased even higher should it be found to be a "large organisation".

Vicky Balch and Leah Washington, who each lost a leg in the crash, were in court for the hearing, along with fellow front-row passengers Joe Pugh and Daniel Thorpe.

Chandaben Chauhan, who was in the second row and was also seriously hurt, also attended.